I took advantage of the nice weather this weekend to take care of some overdue maintenance on my 86 744T. I drove to central PA, about 250 miles from NYC. On the way down, I recorded app. 22 mpg.

Over the weekend, I replace the air filter (the old one didn't look too bad, but it was a pain to open the air box, so I figured what the heck.

I changed spark plugs 1 and 2. I tried to change 3 and 4, but 3 would not screw all the way out, and I feared that whoever changed the plugs previously may have cross-threaded it, so put it back in. No. 4 wouldn't budge, so I'm leaving those for now.

Finally, I did some maintenance on the PCV system. The hose from the oil separator to the Y fitting had cracked when I replaced the engine wiring harness (it has been taped up since), so I replaced that.

While poking around I came across a rubber hose that led to nowhere, and upon closer inspection, I noticed that the tip of the Y fitting had broken off. Took care of that with a new Y fitting.

Gas mileage on the way home: 28.8 mpg.

What did I do right? Does a properly operating PCV system make that much of a difference?

Joe